<?php

abstract class Kd_Data_Dcl_Expression_Fn_String_Base extends Kd_Data_Dcl_Expression_Fn_Base {

	protected function __construct() {
		parent::__construct();
	}

	protected function stringOrField($string){
		if(is_string($string)){
			if($string[0] == "'" && substr($string, -1) == "'"){
				return $string;
			}elseif($string[0] == ':'){
				return $string;
			}else{
				return new Kd_Data_Dcl_Expression_Field($string);
			}
		}
		return $string;
		 
	}
}